* [PATCH v2] iommu/arm-smmu: Fix arm_smmu_device refcount leak in address translation
@ 2021-06-10 2:49 Xiyu Yang
2021-06-10 22:28 ` Rob Clark
2021-06-11 16:15 ` Will Deacon
0 siblings, 2 replies; 3+ messages in thread
From: Xiyu Yang @ 2021-06-10 2:49 UTC (permalink / raw)
To: Will Deacon, Robin Murphy, Joerg Roedel, Rob Clark, Jon Hunter,
Krishna Reddy, Jordan Crouse, Sai Prakash Ranjan,
linux-arm-kernel, iommu, linux-kernel
Cc: yuanxzhang, Xiyu Yang, Xin Tan
The reference counting issue happens in several exception handling paths
of arm_smmu_iova_to_phys_hard(). When those error scenarios occur, the
function forgets to decrease the refcount of "smmu" increased by
arm_smmu_rpm_get(), causing a refcount leak.
Fix this issue by jumping to "out" label when those error scenarios
occur.
Signed-off-by: Xiyu Yang <xiyuyang19@fudan.edu.cn>
Signed-off-by: Xin Tan <tanxin.ctf@gmail.com>
---
drivers/iommu/arm/arm-smmu/arm-smmu.c | 8 ++++++--
1 file changed, 6 insertions(+), 2 deletions(-)
diff --git a/drivers/iommu/arm/arm-smmu/arm-smmu.c b/drivers/iommu/arm/arm-smmu/arm-smmu.c
index 6f72c4d208ca..3a3847277320 100644
--- a/drivers/iommu/arm/arm-smmu/arm-smmu.c
+++ b/drivers/iommu/arm/arm-smmu/arm-smmu.c
@@ -1271,6 +1271,7 @@ static phys_addr_t arm_smmu_iova_to_phys_hard(struct iommu_domain *domain,
u64 phys;
unsigned long va, flags;
int ret, idx = cfg->cbndx;
+ phys_addr_t addr = 0;
ret = arm_smmu_rpm_get(smmu);
if (ret < 0)
@@ -1290,6 +1291,7 @@ static phys_addr_t arm_smmu_iova_to_phys_hard(struct iommu_domain *domain,
dev_err(dev,
"iova to phys timed out on %pad. Falling back to software table walk.\n",
&iova);
+ arm_smmu_rpm_put(smmu);
return ops->iova_to_phys(ops, iova);
}
@@ -1298,12 +1300,14 @@ static phys_addr_t arm_smmu_iova_to_phys_hard(struct iommu_domain *domain,
if (phys & ARM_SMMU_CB_PAR_F) {
dev_err(dev, "translation fault!\n");
dev_err(dev, "PAR = 0x%llx\n", phys);
- return 0;
+ goto out;
}
+ addr = (phys & GENMASK_ULL(39, 12)) | (iova & 0xfff);
+out:
arm_smmu_rpm_put(smmu);
- return (phys & GENMASK_ULL(39, 12)) | (iova & 0xfff);
+ return addr;
}
static phys_addr_t arm_smmu_iova_to_phys(struct iommu_domain *domain,
--
2.7.4
^ permalink raw reply related [flat|nested] 3+ messages in thread* Re: [PATCH v2] iommu/arm-smmu: Fix arm_smmu_device refcount leak in address translation
2021-06-10 2:49 [PATCH v2] iommu/arm-smmu: Fix arm_smmu_device refcount leak in address translation Xiyu Yang
@ 2021-06-10 22:28 ` Rob Clark
2021-06-11 16:15 ` Will Deacon
1 sibling, 0 replies; 3+ messages in thread
From: Rob Clark @ 2021-06-10 22:28 UTC (permalink / raw)
To: Xiyu Yang
Cc: Will Deacon, Robin Murphy, Joerg Roedel, Jon Hunter,
Krishna Reddy, Jordan Crouse, Sai Prakash Ranjan,
moderated list:ARM64 PORT (AARCH64 ARCHITECTURE),
iommu, LKML, yuanxzhang, Xin Tan
On Wed, Jun 9, 2021 at 7:50 PM Xiyu Yang <xiyuyang19@fudan.edu.cn> wrote:
>
> The reference counting issue happens in several exception handling paths
> of arm_smmu_iova_to_phys_hard(). When those error scenarios occur, the
> function forgets to decrease the refcount of "smmu" increased by
> arm_smmu_rpm_get(), causing a refcount leak.
>
> Fix this issue by jumping to "out" label when those error scenarios
> occur.
>
> Signed-off-by: Xiyu Yang <xiyuyang19@fudan.edu.cn>
> Signed-off-by: Xin Tan <tanxin.ctf@gmail.com>
> ---
> drivers/iommu/arm/arm-smmu/arm-smmu.c | 8 ++++++--
> 1 file changed, 6 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/iommu/arm/arm-smmu/arm-smmu.c b/drivers/iommu/arm/arm-smmu/arm-smmu.c
> index 6f72c4d208ca..3a3847277320 100644
> --- a/drivers/iommu/arm/arm-smmu/arm-smmu.c
> +++ b/drivers/iommu/arm/arm-smmu/arm-smmu.c
> @@ -1271,6 +1271,7 @@ static phys_addr_t arm_smmu_iova_to_phys_hard(struct iommu_domain *domain,
> u64 phys;
> unsigned long va, flags;
> int ret, idx = cfg->cbndx;
> + phys_addr_t addr = 0;
>
> ret = arm_smmu_rpm_get(smmu);
> if (ret < 0)
> @@ -1290,6 +1291,7 @@ static phys_addr_t arm_smmu_iova_to_phys_hard(struct iommu_domain *domain,
> dev_err(dev,
> "iova to phys timed out on %pad. Falling back to software table walk.\n",
> &iova);
> + arm_smmu_rpm_put(smmu);
> return ops->iova_to_phys(ops, iova);
I suppose you could also:
addr = ops->iov_to_phys(...);
goto out;
but either way,
Reviewed-by: Rob Clark <robdclark@chromium.org>
> }
>
> @@ -1298,12 +1300,14 @@ static phys_addr_t arm_smmu_iova_to_phys_hard(struct iommu_domain *domain,
> if (phys & ARM_SMMU_CB_PAR_F) {
> dev_err(dev, "translation fault!\n");
> dev_err(dev, "PAR = 0x%llx\n", phys);
> - return 0;
> + goto out;
> }
>
> + addr = (phys & GENMASK_ULL(39, 12)) | (iova & 0xfff);
> +out:
> arm_smmu_rpm_put(smmu);
>
> - return (phys & GENMASK_ULL(39, 12)) | (iova & 0xfff);
> + return addr;
> }
>
> static phys_addr_t arm_smmu_iova_to_phys(struct iommu_domain *domain,
> --
> 2.7.4
>
^ permalink raw reply [flat|nested] 3+ messages in thread* Re: [PATCH v2] iommu/arm-smmu: Fix arm_smmu_device refcount leak in address translation
2021-06-10 2:49 [PATCH v2] iommu/arm-smmu: Fix arm_smmu_device refcount leak in address translation Xiyu Yang
2021-06-10 22:28 ` Rob Clark
@ 2021-06-11 16:15 ` Will Deacon
1 sibling, 0 replies; 3+ messages in thread
From: Will Deacon @ 2021-06-11 16:15 UTC (permalink / raw)
To: Sai Prakash Ranjan, Jordan Crouse, Xiyu Yang, Krishna Reddy,
Rob Clark, Joerg Roedel, Robin Murphy, linux-arm-kernel,
Jon Hunter, linux-kernel, iommu
Cc: catalin.marinas, kernel-team, Will Deacon, Xin Tan, yuanxzhang
On Thu, 10 Jun 2021 10:49:20 +0800, Xiyu Yang wrote:
> The reference counting issue happens in several exception handling paths
> of arm_smmu_iova_to_phys_hard(). When those error scenarios occur, the
> function forgets to decrease the refcount of "smmu" increased by
> arm_smmu_rpm_get(), causing a refcount leak.
>
> Fix this issue by jumping to "out" label when those error scenarios
> occur.
Applied to will (for-joerg/arm-smmu/updates), thanks!
[1/1] iommu/arm-smmu: Fix arm_smmu_device refcount leak in address translation
https://git.kernel.org/will/c/7c8f176d6a3f
Cheers,
--
Will
https://fixes.arm64.dev
https://next.arm64.dev
https://will.arm64.dev
^ permalink raw reply [flat|nested] 3+ messages in thread
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2021-06-10 2:49 [PATCH v2] iommu/arm-smmu: Fix arm_smmu_device refcount leak in address translation Xiyu Yang
2021-06-10 22:28 ` Rob Clark
2021-06-11 16:15 ` Will Deacon
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